Final answer:
The true statement is that VLANs are logical broadcast domains. They divide a network into separate virtual networks, isolate broadcast traffic, and use trunk ports to exchange VLAN information.
Step-by-step explanation:
The correct statement is a. VLANs are logical broadcast domains. VLANs, or Virtual Local Area Networks, are a way to logically divide a physical network into multiple virtual networks. Each VLAN operates as a separate broadcast domain, meaning that broadcast traffic within one VLAN is isolated from other VLANs.
This division is done at the data link layer (Layer 2) of the OSI model, not at the Transport layer. VLANs are implemented using switches, which are able to forward traffic between ports that are members of the same VLAN, but not between ports in different VLANs.
To exchange VLAN information, VLANs use special trunk ports rather than access ports. Trunk ports carry traffic for multiple VLANs, while access ports are associated with a specific VLAN.